public class XinSingleton{
    private XinSingleton(){}
    private static class LazyHolder{
        static final XinSingleton INSTANCE = new XinSingleton();
    }
    public static XinSingleton getInstance(){
        return LazyHolder.INSTANCE;
    }
    public static void main(String[] args) {
        System.out.println("this is " + getInstance());
        
    }
}